V wire cable



(No Model.)

i A. J. MOXHAM.

WIREv CABLE.

10.362,649. Patentedmay 10,1887. l

UNITED STATES gllzrrinsrr OFFICE.

ARTHUR Moxn'amorj JoHNsroWN, rnnnsrnvAnial waas CABLE.

sencrrIcATroN forming pm of Letters raten; No, 362.649', dates M Applicant med critter 1, rees..` serial No. `1vs.2o. No modem To all whom it nitty fcoitcezpn.l

Beit known that l' 'ARTHUR J. MoxHAM,

of Johnstown, in-thecou'ntyof Cambria and In the accompanying drawings, Figure 1 shows in cross-section "a 'cable composed of certain exterior and in'teriorrparts, as--hereinafter described. Fig.2 sho'wsl in 'cross-section a cable of modified interior, [being made of two series of solid strands. -Fig. 3 shows in cross-section a cable with a large flexible core.

Fig. 4 shows insideview a vpiece of finished cable having a cross-section like Fig. 1. Fig. 5 lllustrates a piece of one exterior solid strand of cable coiledor twisted before being laid up with the other strands forming the cable. Fig. 6 shows in cross-section .a cable further n'odi- -fed having two series oi' strands, .cnc of the seriesbeing of solid wire and the other of finer laid-up wires around a iiex-ible core.'

In the several igures of the drawings, the letter A indicates a flexible core ofhemp or other lexiblematerial; B, a series of external solid strands of wire separately formed into permanent helices, as shown in Fig. 5, before being'laid up together into a cable; b, one se `ries of internal solid strands of wire forming a hollow core for the external strands, B, as shown in Fig. 2,- and c a series of internal laid-up strands of fine wires of Iordinary construction, which strands, as shown in Fig. 6, surround the flexible internal core,.Aand are themselves covered by the external solid strands, B.

The solid strands inall the cables shown arev preferablygiven their separate helical set as well as laid up together in their cold statelfor reasons fully set forth in my pending application for process of cable-making, Serial No. 143,336, filed September 17, 18,84; but a cable composed-of solid strandsof wire cannot be made ,even cold. bythe ordinary method-of making cables. llt-the straight wires be coldtwisted directly `around an interior flexible core, said core cannot resist the-tendency of each' wire not toaccommodate itself toits new shape-in other words, to untwist.v Onl the other hand, the solid strands ofV -the cable herein described and claimed being first vgiven a helical set of suitable pitch around a mandrel, or by other machinery, before being laid up into a cable, such cable'obviates the above-mentioned disadvantage vand presents some other advantages, as belowi'set forth.

It has been found in practice that great care is demanded in the use of ordinary tractioncables in motion under great tensiomin order to avoid all kinks and smal-l spherical angles, for in steel and iron of all forms constantlyrecurring changes of form soon destroythe metal hence the more flexible a cable is the more quickly it will yield to .those changes of Y `form to which it may be exposed or subjected by its actuating mechanism. Therefore, while ,av certain degree of flexibility is a necessity,

any excess of iiexibility only increases the levil and tendency In thei-'nvention hereindescribed and claimed to such evil just described.

the increased rigidity oiered by the exterior seA solid strands while permitting sufficient exi# Y `bility resists to `a greater extent thanthe 0rdinary cable any unnecessary or undesirable change of form. v i

.In any cable, ifv -considered as a flexible beam, itis evident that its center vshould preferably be iiexible, such center being its neutral axis. It is also evident that from such axis the iexibility should decrease toward the exterior of the cable until the maxi-` mum rigidity is reached at the. external surface of the cable. whemtherefore, in the cable herein described more than one series of solid strands are required to secure the de. sired .strength and diameter of cable, this re .sult can manifestly be obtained by makingeach internal series of such strands smaller in diameter than its contiguousexterior series until the centeror core is reached, .which center or core should preferably be, as is commonly the case, of some much more iiexible material than that used for the strands proper.

ICO

The same result is also practically obtained when but a single series of solid strands is coiled, as herein described, over or upon a central fi'exible core. Thcintcrior may, therefore, consist, when desired, ofeithera solid or a laidup strand ot' suitable diameter, or of any interior of suitable material without departing from the principle of this invention, such core being made of material having greater flexibility than its outlying strands.

The explanations above made equally apply if the eablebc considered as subjected to a direct tensile strain only, for in such case the first resistance to change o f form is that of the friction of the exterior strands, one against the other. compression of the interior and center. If the friction aforesaid be excessive, the outside strands will rupture before the center is compressed; hence excessive friction of the exterior strands should be avoided. 4If the friction of such strands be reduced within requisite limits, so as to permit the interior strands or core to take ,part in resisting the strain, then such interior should be capable of yielding to a snfic-ient extent to at least take its proper part inthe general resistance. If an absolutely-rigid core be used, the whole strain tending to rupture, or the whole resistance to such strain, will fall upon the exterior strands in case vof excessive friction between such strands, or upon the interior or core in case of deficient friction between the exterior strands.

In neither of these cases, therefore, would the.y ca ble be homogeneous; but by making the ilexi-v bility such that it continuously increases from the exterior to the interior, as is the casein the arrangements of strands herein described, the desired homogeneity is attained. l

In the construction of cables with solid exterior strands of wire, such as are herein del scribed and claimed, it is of importance to observe the following points: Said solid strands must not exceed a given or predetermined degree of' flexibility; hence the diameter for each wire becomes a xed thing or constantas soon as this limit is reached; and with regard to a flexible core it would manifestly be a serions error to make the flexible core of a diameter so large as to exceed too much the diameter of the neutral axis proper, as is illustrated in Fig.

The `tendency ensuing is to` -3. Therefore the space contained between the exterior strands and any core, in consequence of thus fixing their respective diameters, may

be filled up with two or more internal series of strands of di fferent diameters--that is, decreasing from the circumference toward the center-as hereinbeforc explained. Should any portion' of' they `space to be filled, however,

be too large for one series of interior solid 6o strands and not large enough for two such scries, such space may be filled with a single series of strands of suitable diameter, made of twisted or laid-up fine wires-such as are used for strands of ordinary cables-as is illustrated 6 3 in Fig. 6. The desired flexibility of cable, together with the necessary occupation of space, can thus always be secl red with great accuracy v of design.

In wire-rope cables as commonly construct- 7o ed the interlocking ofthe wires composing the outer strands induces excessive friction, so great, indeed, as to throw the greatest strains and tension to which the cable is subjected upon these exterior strands. .The elongation ot' such cables previous to rupture under excessive strains, it is known'from experience, is very small; but by using solid strands, as herein described, for exterior` strands, such elongation is increased, and the freedom from excessive friction between said strands permits the internal parts of thc cable to bear their proper proportional parts of the strain.

I am aware thatithas been proposed to make a hollow' lightning-conductor of solid twisted wires, and such an article I do not claim, but limit myself to the cable herein described, made of solid exterior strands and interior of more flexible construction, whether of one or' more of the forms of' such described interiors.

Having thus fully described my said new form of cable as of my invention, I claim- As a new article of manufacture, a traction wire cable composed of helically-twisted solid strands of' wire laid u p together and combined, as described, with a more flexible interior or core, substantially as and for the purposes set forth.

ARTHUR J. MOXHAM.

Vitnesses: A EDGAR C. MoxHAM, A. MONTGOMERY. 

